Physiology of Pectoralis
Physiology of Pectoralis Major
The function of the pectoralis major is different for its different heads.
- The clavicular head flexes the humerus, and
- the sternocostal head adducts the humerus.
As a whole the action is to adduct and medially rotate the humerus. It also draws the scapula anteriorly and inferiorly.
Physiology of Pectoralis Minor
Stabilizes the scapula by drawing it inferiorly and anteriorly against the thoracic wall, raises ribs in inspiration.
The Pectoral Girdle
There is a pectoral girdle above each arm, consisting of a scapula (shoulder blade) and a clavicle (collar bone). The shoulder girdle, also known as the pectoral girdle, forms a socket and support system for the upper limb
The scapula is a strong bone and protects the posterior upper chest.